A Nassau County narcotics detective "clearly falsified" police paperwork at least once, according to the president of a defense attorney association, which is calling for prosecutors to expand their investigation into the detective's conduct.

The Nassau district attorney's office began probing the actions of Det. Michael Cipullo after learning that a confidential informant he paid to do a drug buy in Oceanside last year wasn't part of the transaction.

Acting District Attorney Madeline Singas' office has so far sent 16 letters to attorneys who represent defendants with open cases involving Cipullo, notifying them about his conflicting statements in the Oceanside case, said Singas spokesman Paul Leonard.

PhotosRecent LI mug shotsDataLI crime stats

The letters were "in furtherance of ensuring that no individual is unjustly convicted," Leonard said.

But in a March 11 letter to Singas, Dana Grossblatt, head of the county's Criminal Courts Bar Association, called for prosecutors to review all cases involving Cipullo going back at least five years, including closed cases.

Grossblatt said Cipullo has been involved in multiple arrests leading to dozens of convictions. The Jericho attorney added that while a broadened probe might seem onerous, it would be nothing compared to someone having possibly spent "even one day in jail based upon false allegations supported by this detective's own sworn statements."

advertisement | advertise on newsday

In a written reply to Grossblatt Thursday, Chief Assistant District Attorney Albert Teichman said prosecutors only know of one discrepancy between Cipullo's account of what transpired in a case and his case paperwork.

"The underlying reason for the discrepancy is the focus of the continuing investigation," he wrote, saying any additional actions will be dictated by the probe's results. Teichman said Grossblatt's request to expand the probe is "premature."

In a copy of the letter sent to the defense bar obtained by Newsday, a prosecutor described circumstances that led to the probe. The letter said Cipullo wrote in a report that an informant bought 20 Xanax pills from a defendant in November, and filled out a receipt saying the informant was paid $50 for that work.

But Cipullo later indicated that no informant was part of the alleged purchase from that defendant, and he bought the pills himself, although he did pay the informant, the prosecutor's letter said. The letter also said that in an audio recording of the incident there appeared to be no reference to an informant being present.

Police internal affairs officers are also investigating, and Cipullo was reassigned to administrative duties pending the outcome, a police spokesman said.

The president of Cipullo's union has defended him, saying the 25-year veteran is highly decorated and does "phenomenal" work.